A REPRODUCIBLE METHOD FOR CARIES EVALUATION

III. TEST IN A THERAPEUTIC EXPERIMENT WITH AN AMMONIATED DENTIFRICE

¹ Laboratory of Hygiene, University of Utrecht, Utrecht, Holland

Caries was studied in 166 boys of 10 to 14 years, living in two boarding schools. The boys were carefully divided in two groups with about the same dental history and caries incidence. One group brushed their teeth with an ammoniated dentifrice (5 per cent ammonium phosphate, 3 per cent urea), the other group with a control paste.

Proximal caries in molars and premolars was evaluated from duplicate roentgenograms at the beginning and at the end of the experimental period with a method described previously. The standard error was quite small (0.6 per cent). Table IV summarizes the results. The caries increase after one and one-half years was remarkably equal in both groups.

The use of the ammoniated tooth paste had no effect on caries incidence or on the number of lactobacilli in the saliva (Fig. 4).

The equality of the caries increment in both groups shows the advantages of a careful selection of the experimental and control group and confirms the reproducibility of the used method of caries evaluation.